code: def tocsc(self, copy=False):
      idx_dtype = self._get_index_dtype(
          (self.indptr, self.indices),
          maxval=max(self.nnz, self.shape[0]),
      )
      indptr = np.empty(self.shape[1] + 1, dtype=idx_dtype)
      indices = np.empty(self.nnz, dtype=idx_dtype)
      data = np.empty(self.nnz, dtype=upcast(self.dtype))
  
      csr_tocsc(
          self.shape[0],
          self.shape[1],
          self.indptr.astype(idx_dtype),
          self.indices.astype(idx_dtype),
          self.data,
          indptr,
          indices,
          data,
      )
  
      A = self._csc_container((data, indices, indptr), shape=self.shape)
      A.has_sorted_indices = True
      return A
  
imports: import numpy
  from ._matrix import spmatrix
  from ._base import _spbase, sparray
  from ._sparsetools import csr_tocsc, csr_tobsr, csr_count_blocks, get_csr_submatrix
  from ._sputils import upcast
  from ._compressed import _cs_matrix
label_desc: Use image node_id 4 for calling the _csr_base obj's underlying member method code with example usage: obj.tocsc(copy) and returns: A